I have a gen 1 Apple Watch that was paired to a iPhone that I lost. When I got my replacement iPhone and set it up it did not work correctly and now I can’t unpair my watch from the old phone to pair with the new one.

I have a gen 1 Apple Watch that was paired to a iPhone that I lost. When I got my replacement iPhone and set it up it did not work correctly and now I can’t unpair my watch from the old phone to pair with the new one. I’m worried that if I just reset the watch without unpairing it’s will have the activation lock remain and I will brick it. Currently I can read the time and date but most of the other functions I used are not available.